@article{10_37236_510,
     author = {Chris Godsil},
     title = {Periodic graphs},
     journal = {The electronic journal of combinatorics},
     year = {2011},
     volume = {18},
     number = {1},
     doi = {10.37236/510},
     zbl = {1213.05166},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/510/}
}